This invention relates, generally, to surgical instrumentation and, more particularly, to a surgical instrument for electrosurgical resection.
The medical field has developed various ways of removing tissue from patients. During surgery, medical practitioners may employ an instrument called a xe2x80x9csnarexe2x80x99, in order to remove growths such as polyps. A snare may include a handle and a wire loop. Generally, the wire loop may be controlled by a mechanism in the handle for removal of a growth.
Some surgical instruments utilize electricity. One known surgical snare for removing a polyp includes a proximal finger grip assembly. In particular, a finger grip is slidably mounted for movement between a proximal thumb grip and a spacer block, which is located at the proximal end of a distal, nonconductive, stem assembly. Namely, the stem assembly has a first tube engaged proximally by the spacer block and connected distally to a second tube. Further, the second tube forms a sheath for a lead and loop assembly. The lead can be a wire cable removably connected proximally to a clamping knob of the finger grip assembly, which includes an insulated electrical connector for conducting cutting and coagulation current to the lead and loop assembly in order to remove a polyp over which the loop has been placed. Such a design is disclosed in U.S. Pat. No. 3,828,790 to Curtiss et al. (entitled xe2x80x9cSurgical Snare,xe2x80x9d issued Aug. 13, 1974, and assigned to American Cystoscope Makers, Inc.).
One known monopolar electrosurgical instrument for removal of a pedunculated polyp has a proximal handle member and a distal flexible tube. The flexible tube has an outside diameter sufficiently small to fit through the working lumen of an endoscope-type device. A metallic ring-type surface electrode is mounted near the distal end of the flexible tube. The ring-type electrode is coupled to a first electrical cord which the surgeon can couple to an electrosurgical generator in order to perform coagulation. Furthermore, the surgeon can decouple the first electrical cord from the electrosurgical generator, and instead couple thereto a second electrical cord that is coupled to a pull-wire mounted in a bore formed in the handle member. The pull-wire extends distally through the lumen of the flexible tube and is attached to a loop of bare, electrically conductive wire. Hence, by coupling the second electrical cord to the electrosurgical generator, the surgeon can perform cutting of a pedunculated polyp surrounded by the wire loop. Such a design is disclosed in U.S. Pat. No. 5,158,561 to Rydell et al. (entitled xe2x80x9cMonopolar Polypectomy Snare With Coagulation Electrode,xe2x80x9d issued Oct. 27, 1992, and assigned to Everest Medical Corporation).
A need exists for increasing the precision and effectiveness of cauterization and coagulation using surgical snares. A further need exists for decreasing invasiveness and increasing safety in performing hysterectomies (of which over six hundred thousand are performed in the United States each year), laparoscopic surgeries, and resections of the kidney, spleen, and pancreas. Moreover, it is often desirable to remove a relatively large tumor, for instance, on the uterus (e.g., myofibroma or leiomyoma).
Pursuant to the present invention, the shortcomings of the prior art are overcome and additional advantages provided through the provision of surgical instrumentation that includes an electrosurgical instrument.
In one aspect of the invention, a surgical instrument includes a body, a snare electrode, a spool and an electrical connector. The body has proximal and distal parts. The distal part of the body includes a passageway extending axially therethrough. The passageway has first and second ports. The snare electrode is adapted to telescope in the passageway. The distal part of the body has an outward surface electrically insulated from the snare electrode. The snare electrode includes first and second portions. The second portion of the snare electrode is extendable from the second port of the passageway for forming a loop sized to be placed over tissue to be removed from a patient. The spool is rotatably supported in the proximal part of the body. The first portion of the snare electrode is windable about the spool. A rotation of the spool in a winding direction causes retraction of the first portion of the snare electrode from the first port of the passageway, thereby closing the loop to engage the tissue. The electrical connector is for allowing the snare electrode to be coupled to an electrical source. An electrical current is passed from the electrical source to the loop to cut and cauterize the tissue.
In another aspect of the invention, an outward surface of the proximal part of the body can be electrically insulated from the snare electrode and/or adapted for handling. A driver can be adapted for engagement with the spool. The driver can motivate rotation of the spool.
The driver can allow user switching among operating modes. The operating modes can include first and/or second selections. The first selection can allow winding of a section of the snare electrode about the spool for closing the loop to engage the tissue. The second selection can allow unwinding of a section of the snare electrode from the spool for placing the loop over the tissue and/or relocating the loop.
The proximal part of the body can include and/or be removably engaged with the driver. The driver can be adapted to be coupled with a power source. The power source can include an electrical source, a battery, and/or physical input. The driver can include a electromechanical driver and/or a manual winding mechanism. The manual winding mechanism can comprise the proximal part of the body.
A casing for the driver can include an outward surface electrically insulated from the snare electrode and/or a handle. The spool can include a socket and/or a slot for receiving a shaft of the driver.
The proximal and/or distal parts of the body can include an autoclavable portion. The proximal and/or distal parts of the body can include a disposable portion. The snare electrode can include solid wire, braided wire, and/or fine line cutting wire. The electrical source can allow a selection of at least one electrical frequency for a cauterization of the tissue and/or a coagulation of blood vessels of the patient.
A companion electrode can be selectively coupled to companion the electrical source and to the patient. The electrode can be removably attachable to a shield and/or a cap. A portion of the spool can be slidably engaged with and/or frictionally engaged with a sidewall of the proximal part of the body. The distal part of the body can include a tube, the tube can form the passageway, and the distal part of the body can be formed with non conductive material. The tube can include an opening for accessing, adjusting, and/or severing the snare electrode. It may include another opening for aspiration of smoke. In yet another aspect of the present invention, a surgical instrument includes a body, a snare electrode, a spool and an electrical connector. The body has proximal and distal parts. The distal part of the body has first and second ports. The snare electrode is adapted to telescope in the passageway. The distal part of the body has an outward surface electrically insulated from the snare electrode. The snare electrode includes first and second portions. The cond portion of the snare electrode is extendable from the second port of the passageway for forming a loop sized to be placed over a resection portion of a uterus.
The resection portion of the uterus is to be removed from a patient. The spool is rotatably supported in the proximal part of the body. The first portion of the snare electrode is windable about the spool. A includes a passageway extending axially therethrough. The passageway rotation of the spool in a winding direction causes retraction of the first portion of the snare electrode from the first port of the passageway., thereby closing the loop to engage the resection portion of the uterus. The electrical connector is for allowing the snare electrode to be coupled to an electrical source. An electrical current is passed from the electrical source to the loop to cauterize the resection portion of the uterus.
The invention further contemplates a method for effecting electrosurgical resection. A snare electrode having first and second portions is selected. A body having proximal and distal parts is selected. The distal part of the body includes a passageway extending axially therethrough. The passageway has first and second ports. The snare electrode is telescoped in the passageway, and the second portion of the snare electrode is extended from the second port of the passageway in order to form a loop, where the first portion of the snare electrode is wound about a spool rotatably supported in the proximal part of the body. The loop is sized for placement around a resection portion of an organ. The resection portion of the organ is to be removed from a patient. The spool is rotated in a winding direction to retract the first portion of the snare electrode away from the first port of the passageway, to close the loop and engage the resection portion of the organ. An electrical current is passed from an electrical source to the loop to cautery cut the resection portion of the organ.
In a further aspect of the invention, the rotating of the spool and/or the passing of the electrical current can serve to coagulate blood vessels of the patient. The rotating of the spool can allow user switching among operating modes. The operating modes can include first and/or second selections. The first selection can allow winding of a section of the snare electrode about the spool for closing the loop to engage the organ. The second selection can allow unwinding of a section of the snare electrode from the spool for placing the loop around the organ and/or relocating the loop. The organ can comprise a uterus, gallbladder, liver and/or blood vessel growth or tonsil.
The present invention can be used in standard and minimally invasive surgery. For example, a trocar used in laparocospic surgery or first and second blades of a surgical retractor can be inserted through a small incision into the patient. The first and second blades can be spread to form an operating window at the incision. The spreading of the first and second blades can allow the distal part of the body to be exposed in the operating window.
Thus, the present invention advantageously provides for electrosurgical resection of tissues including large organs such as the uterus with minimal invasiveness, enhanced precision, increased safety and decreased bleeding.